How to Calculate Percentage Increase (Formula, Examples & Common Uses)

A price goes up, a salary gets a raise, a population grows, and almost immediately someone wants to know by how much, expressed as a percentage rather than a raw number. Knowing how to calculate percentage increase is one of the most broadly useful pieces of arithmetic there is, precisely because it shows up in so many unrelated situations.

This guide covers the formula itself, three worked examples covering a salary raise, a price increase, and population growth, how to handle a decrease instead of an increase, and the often-confused difference between percentage increase and percent change.

What Is Percentage Increase?

Percentage increase measures how much a value has grown, expressed as a percentage of its original size. It answers a specific question: relative to where a number started, how much bigger is it now? This relative framing is what makes percentages more useful than raw differences in many situations, since a $10 increase means something very different on a $20 item than it does on a $2,000 item.

That last point is worth sitting with, because it is the entire reason percentages exist as a concept rather than everyone just comparing raw dollar or unit amounts. A $10 increase on a $20 item is a 50% jump, an enormous relative change, while the same $10 increase on a $2,000 item is just 0.5%, barely noticeable. Reporting the raw $10 figure alone hides which of those two situations you are actually looking at, which is exactly the gap percentage increase is designed to close.

The Percentage Increase Formula

Three steps make up this calculation: subtract the original value from the new value to get the absolute change, divide that change by the original value to express it as a fraction of where you started, then multiply by 100 to convert the fraction into a percentage.

It helps to think of the middle step, dividing by the original value, as the part doing the real conceptual work. Subtracting two numbers just tells you the raw size of the gap between them. Dividing that gap by the starting point rescales it relative to where you began, which is what turns an arbitrary dollar or unit figure into a percentage that can be meaningfully compared across completely different situations.

Step-by-Step Examples

Salary raise

A salary moves from $60,000 to $66,000. The change is $6,000. Dividing by the original $60,000 gives 0.10, and multiplying by 100 gives a 10% increase.

Price increase

A product priced at $120 increases to $150. The change is $30. Dividing by the original $120 gives 0.25, and multiplying by 100 gives a 25% increase.

Population growth

A town's population grows from 40,000 to 43,000 over a year. The change is 3,000. Dividing by the original 40,000 gives 0.075, and multiplying by 100 gives a 7.5% increase.

In every case, the structure of the calculation never changes, only the numbers being plugged in.

How to Calculate Percentage Decrease

The formula for a decrease is identical to the increase formula. The only difference is the sign of the result: when the new value is smaller than the original, the change comes out negative, which signals a decrease rather than an increase.

For example, a price dropping from $150 to $120 gives ((120 − 150) ÷ 150) × 100 = −20%. The negative sign simply means the value decreased by 20%, using the exact same formula used for an increase.

Percentage Increase vs Percent Change: What Is the Difference?

In practice, the terms are often used interchangeably, but there is a subtle distinction worth knowing. Percent change is the general, neutral term that covers both increases and decreases. Percentage increase specifically describes a positive change, where the new value is larger than the original. If someone asks for "percent change" and the answer comes out negative, that simply means the change was a decrease rather than an increase, using the same underlying calculation either way.

Real-World Uses of Percentage Increase

• Salary and wage negotiations, where a raise is almost always discussed in percentage terms rather than a flat dollar amount.
• Retail and e-commerce pricing, tracking how much a price has risen compared to a previous sale or list price.
• Investment and savings growth, comparing a portfolio or account balance against where it started over a given period.
• Academic and scientific reporting, describing growth in measurements, populations, or experimental results in a way that is comparable across different starting sizes.
• Business performance reviews, comparing revenue, costs, or headcount period over period in a standardized way.

Frequently asked questions

Once you understand how to calculate percentage increase using the original value as your baseline, the formula scales to any pair of numbers, no matter how large or small. Use the Percentage Increase Calculator above to skip the manual arithmetic entirely and see the percentage, the absolute change, and the formula with your actual numbers substituted in.

If you are working with grades or course averages, see how to calculate GPA step by step , or if you need to convert a measurement into a usable fraction, see how to convert a decimal to a fraction.